I have been chasing a transmit issue. Make sure that the micro switch key is not shorted closed, the key ja k not shorted closed. Look at the tx and sig gen lines feeding the pa to make sure that either is not turned on all the time. It takes one high enable signal and the clock signal to turn them on. Look at Q6 to make sure it is turned off when in receive. My Q6 was shorted and the pa was turned on even when tx was off. My place to start would be the key lines and make sure they are not shorted to ground, turning the pa on even out of transmit.
